Hi.

I have many IBM 4694 - 104 P.O.S, but in Linux dont work the ports RS485..

I need control Scanner, Register, and keyboard and other devices RS485.

Somebody know a Linux Kernel Module with support for Ports RS485 ?? This computer have UART TI16450.

With one converter RS232 to RS-485 i can control many devices?

Thanks for your help!

 

We've had good luck with the Microscan MS-5000 multidrop concentrator. It has
a simple RS232 interface for host communication to an RS485 network. The vendor is at
Microscan Systems, Inc.,
1201 S. W. 7th Street,
Renton, Washington, U. S. A. 98055
(425) 226- 5700
FAX: (425) 226- 8682

www.microscan.com

 

Hi Paulo

> I have many IBM 4694 - 104 P.O.S, but in Linux dont work the ports RS485..

I'm mot sure I understand this as most 485 cards have a standard UART
interface. Converters on the rs232 ports shouldn't be a problem either.

> I need control Scanner, Register, and keyboard and other devices RS485.

Yes

> Somebody know a Linux Kernel Module with support for Ports RS485 ?? This
> computer have UART TI16450.

There are physical differences, you can't convert with software. The standard serial driver should work fine with a 485 card or your serial ports with converters.

> With one converter RS232 to RS-485 i can control many devices?

Perhaps.

I don't know exactly what IBM 4964 - 104's do amongst their parts but once you get your wire spec right you can use a freeware datascope to find out. Try a surplus dealer for manuals, IBM is pretty good about documenting the zany stuff they do in front of concentrators. I used to do hostile system changeovers in the hospital business. It takes some digging but it almost always makes sense in an IBM kind of way and a lot of people know how.

Regards

cww Who doesn't do BiSync anymore.

 

Linux won't deal with the 485 port directly. Heck, nothing does! In our
product, we've got a standard 16550 UART. To switch it between 232 and 485,
I've got some code that pokes an FPGA registers to get it to switch the output and deal with requirements of the 485 line (the fact that you have to raise the line high when using it, and drop it afterwards).

Some 485 ports use the RTS/CTS lines to do this. Some of them use dip switches on the back. I bet some of them use jumpers. You're going to have to check with your IBM rep or look in the manual to find out how to do it on your specific piece of hardware.

RS-232 to RS-485 convertors are an easy solution (but of course, are more
expensive that using the ones already on the box). I don't know about the
feasiblity of using disimilar devices on ONE RS-485 line... that strikes me as a recipe for disaster as they could have different comm settings as well as incompatible protocols (which would cause two to respond at once).

Good luck!

Alex Pavloff
Software Engineer
Eason Technology

 

|
|With one converter RS232 to RS-485 I can control many devices?
|

The converter does not bother about the number of devices connected. It just
puts whatever you say to the 485 bus and gives you whatever comes to you
from the bus. You can control many devices with a single rs485 bus. But
watch out for protocol mismatches.

Lakshmi Anand K, MSPV, Pavoorchatram - 627808
----------------------------
http://www.lakshmianandk.com/